This chapter has sooo many key terms. Yuck.
Terms : Hide Images
| 58825261 | Microevolution | Evolutionary change below the species level; change in the genetic makeup of a population from generation to generation. | 0 | |
| 58825262 | Population genetics | The study of how populations change genetically over time | 1 | |
| 58825263 | Modern Synthesis | A comprehensive theory of evolution emphasizing populations as units of evolution and integrating ideas from many fields, including genetics, statistics, paleontology, taxonomy, and biogeography. | 2 | |
| 58825264 | Population | A localized group of individuals that belong to the same biological species (that are capable of interbreeding and producing fertile offspring). | 3 | |
| 58825265 | Gene pool | The total aggregate of genes in a population at any one time. | 4 | |
| 58825266 | Hardy-Weinberg theorem | The principle that frequencies of alleles and genotypes in a population remain constant from generation to generation, provided that only Mendelian segregation and recombination of alleles are at work. | 5 | |
| 58825267 | Conditions of Hardy-Weinberg Equilibrium | 1. Extremely large population size: The smaller the population, the greater the role played by chance fluctuations in allele frequencies from one generation to the next, known as genetic drift. 2. No gene flow: Gene flow, the transfer of alleles between populations, can alter allele frequencies. 3. No mutations: By introducing or removing genes from chromosomes or by changing one allele into another, mutations modify the gene pool. 4. Random mating: If individuals preferentially choose mates with certain genotypes, including close relatives (inbreeding), random mixing of gametes does not occur. 5. No natural selection: Differential survival and reproductive success of individuals carrying different genotypes will alter allele frequencies. | 6 | |
| 58825268 | Mutations | Changes in the DNA of a gene, ultimately creating genetic diversity. | 7 | |
| 58825269 | Genetic Drift | Unpredictable fluctuations in allele frequencies from one generation to the next because of a population′s finite size | 8 | |
| 58825270 | Bottleneck effect | Genetic drift resulting from the reduction of a population, typically by a natural disaster, such that the surviving population is no longer genetically representative of the original population. | 9 | |
| 58825271 | Founder Effect | Genetic drift that occurs when a few individuals become isolated from a larger population, with the result that the new population′s gene pool is not reflective of the original population. | 10 | |
| 58825272 | Gene flow | Genetic additions to or substractions from a population resulting from the movement of fertile individuals or gametes. | 11 | |
| 58825273 | Phenotypic Polymorphism | The existence of two or more distinct morphs (discrete forms), each represented in a population in high enough frequencies to be readily noticeable | 12 | |
| 58825274 | Morphs | The potential phenotypic variants of an organism. When individuals differ in a discrete character, the different forms are called ______________________. | 13 | |
| 58825275 | Genetic Polymorphism | The existence of two or more distinct alleles at a given locus in a population′s gene pool. | 14 | |
| 58825276 | Average heterozygosity | The percent, on average, of a population′s loci that are heterozygous in members of the population | 15 | |
| 58825277 | Geographic Variation | Differences between the gene pools of separate populations or population subgroups | 16 | |
| 58825278 | Cline | A graded variation in a trait that parallels a gradient in the environment | 17 | |
| 58825279 | Fitness | The contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals. | 18 | |
| 58825280 | Relative Fitness | The contribution of one genotype to the next generation compared to that of alternative genotypes for the same locus | 19 | |
| 58825281 | Directional Selection | Natural selection that favors individuals at one end of the phenotypic range. | 20 | |
| 58825282 | Disruptive Selection | Natural selection that favors individuals on both extremes of a phenotypic range over intermediate phenotypes. | 21 | |
| 58825283 | Stabalizing Selection | Natural selection that favors intermediate variants by acting against extreme phenotypes | 22 | |
| 58825284 | Balancing Selection | Natural selection that maintains stable frequencies of two or more phenotypic forms in a population (balanced polymorphism) | 23 | |
| 58825285 | Balanced Polymorphism | The ability of natural selection to maintain diversity in a population. | 24 | |
| 58825286 | Heterozygote advantage | Greater reproductive success of heterozygous individuals compared to homozygotes; tends to preserve variation in gene pools. | 25 | |
| 58825287 | Frequency-dependent selection | A decline in the reproductive success of a morph resulting from the morph′s phenotype becoming too common in a population; a cause of balanced polymorphism in populations. | 26 | |
| 58825288 | Neutral Variation | Genetic diversity that confers no apparent selective advantage. | 27 | |
| 58825289 | Pseudogenes | DNA segments very similar to a real gene but which do not yield a functional product; a gene that has become inactivated in a particular species because of mutation. | 28 | |
| 58825290 | Sexual Selection | Natural selection for mating success. | 29 | |
| 58825291 | Sexual Dimorphism | A special case of polymorphism based on the distinction between the secondary sex characteristics of males and females. | 30 | |
| 58825292 | Intrasexual Selection | A direct competition among individuals of one sex (usually the males in vertebrates) for mates of the opposite sex. | 31 | |
| 58825293 | Intersexual Selection | Selection whereby individuals of one sex (usually females) are choosy in selecting their mates from individuals of the other sex; also called mate choice. | 32 |
